The head of Britain’s environmental watchdog has branded the third runway at Heathrow airport a 'mistake', saying it is unlikely to be built because of the huge political uncertainty surrounding the project.

Lord Smith of Finsbury, chairman of the Environment Agency, said there was 'a very big chance' that the project would stall given the threat of legal action from campaigners and resistance from the Tories and Liberal Democrats.

'I think they are making a mistake for a number of reasons,' he said. 'It [the opposition] will evidently make it much more difficult for BAA [the airports operator] to make the decision to proceed with extensive planning and design work,' he said.

Financial Times